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-   -   FT101E -100 volts DC? (https://www.vintage-radio.net/forum/showthread.php?t=156548)

Louis-Philippe 15th May 2019 5:05 am

FT101E -100 volts DC?
 
Hello, I have a Yaesu FT101E and I always wondered why Yaesu indicte on its panel rectifier (PB-1076b) an output at -100 volt DC. In reality it produces a voltage of more than -160 volts. In the schematic of the service manual, the output -100 volts DC and 160 volt DC are produced by the same voltage doubler. is this normal?

Louis Philippe. 73 VE2PBC

PeterRoberts 26th May 2019 4:35 pm

Re: FT101E -100 volts DC?
 
Hi,

This is normal. The early FT-101 did use a slightly different circuit on PB1076 and used -100V, but this was changed on later models to -160V. However, Yaesu never got around to updating the schematics and manuals to reflect this, so it remains shown as a "-100V" level but in reality is more like -160V.

I think my 101E measures about -170V.

73,

Peter

G4DJB

Louis-Philippe 27th May 2019 2:10 am

Re: FT101E -100 volts DC?
 
Thank you Peter, I am very happy to finally have an explanation. Me too I get -169 volts DC. I'm realigning my FT101E to bring it back to life. Thanks again Louis-Philippe 73 VE2PBC

PeterRoberts 27th May 2019 11:47 am

Re: FT101E -100 volts DC?
 
You are welcome Louis-Philippe. You may find other differences between the schematics and what is actually inside the rig. Yaesu were obviously not very good at updating their documentation when making design changes,

Good luck with the alignment - it is very time consuming to get it just right, but very necessary!

73,

Peter


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